<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--div称为块级分区元素: 独占一行-->
<div>div1</div><div>div2</div><div>div3</div>
<!--span行内分区元素: 共占一行-->
<span>span1</span>
<span>span2</span>
<span>span3</span>
<div>头</div>
<div>体</div>
<div>脚</div>
<!--HTML5新增分区元素,作用和div一样都是独占一行,目的:提高代码可读性-->

<header>头</header>
<main>
  <nav>导航区</nav>
  主体
  <section>区域1</section>
  <section>区域2</section>
  <section>区域3</section>
</main>
<footer>脚</footer>




</body>
</html>